In the Linux kernel, the following vulnerability has been resolved: iio: health: max30102: fix NULL dereference in interrupt handler The i

In the Linux kernel, the following vulnerability has been resolved:

iio: health: max30102: fix NULL dereference in interrupt handler

The interrupt is requested in max30102_probe() and stays enabled
for the lifetime of the device, but indio_dev->active_scan_mask is only
valid while a buffer is enabled. When an interrupt arrives while no
buffer is enabled, the handler dereferences the NULL active_scan_mask:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Call trace:
__bitmap_weight+0x64/0x98 (P)
max30102_interrupt_handler+0x48/0x160 [max30102]

Call max30102_fifo_count() at the top of the handler and return early
unless it reports a FIFO sample is ready. Because FIFO_RDY is the only
interrupt source enabled in max30102_chip_init(), an invocation of
max30102_interrupt_handler() without the FIFO_RDY interrupt status bit
set carries no data to read and can return before touching
active_scan_mask. A negative return from max30102_fifo_count()
indicates a failed interrupt status read and is treated the same way.